Damaged Files

Sometimes Inventor refuses to open a file and shows a message like "Error loading segment PmGraphicsSegment in database". The model may be perfectly fine underneath - or parts of it may be gone. MetaReader reads straight past whatever trips Inventor up, so it can open the file, tell you what kind of damage it has, and, when the damage is the fixable kind, repair it in place.

The "Damaged file" badge

Open a file with this kind of damage and a red Damaged file badge appears under the document title. Hover it for the details: which segments are affected, and what exactly is wrong. There are two very different cases, and the badge tells them apart.

Repairable: a stale segment registry

Inside every Inventor file, a small registry records how many blocks each internal database segment should have. If some tool rewrote the file's streams without refreshing that registry, the counts no longer match what's actually stored - and Inventor hard-stops the open with the segment error, even though no model data is missing. Only the bookkeeping drifted.

This is repairable. When MetaReader sees it, the badge shows a Repair button:

• Repair rewrites just the registry counts to match the data that's really there. No geometry, features or properties are touched.
• Before it writes anything, MetaReader saves an untouched backup copy next to the file, named yourfile.ipt.pre-repair.bak. If anything looks wrong afterwards, that copy is your original.
• The first time you use it, MetaReader asks you to confirm you understand that the repair rewrites the file's internal database - it's a rescue tool, not an everyday action.

After a successful repair the badge turns into a green Repaired chip with an Open in Inventor button, so you can confirm the file opens before you rely on it.

Not repairable: destroyed segment data

The other case is real data loss. Runs of zeroed bytes sit where compressed geometry used to be - the signature of a disk fault or an interrupted copy or transfer. Those bytes are physically gone, the compressed stream can't be re-synchronized past the gap, and Inventor needs every segment intact to open a file.

MetaReader detects this too, and is honest about it: no Repair button appears, because no repair could work. The badge names the affected segments and how much still reads, and tells you the only real fix - restore the file from a backup (Vault or another PDM, the OldVersions folder next to the file, or a file backup). MetaReader never offers a repair that would only produce a file that still won't open.

Even for an unrepairable file, everything MetaReader reads from metadata - iProperties, the preview thumbnail, referenced files, version history - is still available, which is often enough to identify the file and find the right backup to restore.

From the command line

The command-line tool makes the same distinction without the app. invmeta segments <file> inventories the internal databases and flags any damage; invmeta repair <file> fixes a stale registry in place (writing the same .pre-repair.bak backup first) and refuses a file whose data is destroyed. See Command line.

For what these segments and registries actually are, see How it works.